1. Field of the Invention
The present invention relates to reclosable packages and a method of manufacture thereof, wherein a semi-circular or similarly shaped perforated pattern is punched in the web in registration with the package side seals. Additionally, continuous lines of perforation are punched in the web parallel to the top of the package. The web is folded and shaped into a package with a header which includes the semi-circular perforated pattern and the lines of perforation. The method includes both machine direction and transverse direction embodiments.
2. Description of the Prior Art
In the prior art, methods of manufacture of reclosable packages with tear-away headers are well-developed and satisfactory for their intended purposes. In particular, form fill seal (FFS) methods are used to produce these reclosable packages which are very advantageous in that they are tamper-evident while maintaining a simple construction with relatively low manufacturing costs.
Typically, slider zipper packages are manufactured on vertical form fill seal (VFFS) machines using low density polyethylene (LDPE) films. The walls of the package extend above the slider to form a tamper-evident header and a line of perforations extends across the header at an elevation below the zipper profile. When the side seals of the package are made, the header becomes sealed to the flanges of the zipper at an elevation above the line of perforations, making it difficult to remove the header.
Additionally, slider operated reclosable packages with a removable header have typically been produced from relatively high cost laminate films as such films lend themselves to laser scoring. The laser scoring can be configured in that the resulting perforations are above the zipper profile in the area of the side seals and drops below the level of the profile along the area of the package top away from the side seals. The consumer can remove the package header to access the slider of the zipper without being impeded by the header film.
On the other hand, unsupported or non-laminate films tend to stretch and do not tear well when laser scored. These films are typically perforated in order to create a removable header. However, the perforations for removable headers for reclosable packages using such material have typically been limited to straight lines above the zipper. This has been acceptable for non-slider applications having a portion of the header above the zipper, but has been open to improvement for slider zipper applications where it is preferable to have the header tear off below the zipper to improve access to the slider.